


Resonance

by StarlightKnight



Category: Senki Zesshou Symphogear
Genre: Bad End AU, Biblical Scripture References (Abrahamic Religions), Canon-Typical Violence, F/F, One Shot, Post-Canon, Revelations, Spoilers, Time Travel Fix-It, man the drugs were good back then
Language: English
Status: Completed
Published: 2020-07-05
Updated: 2020-07-05
Packaged: 2021-03-04 20:07:58
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 3,794
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25082119
Author URL: https://archiveofourown.org/users/StarlightKnight/pseuds/StarlightKnight
Summary: The sunrise on the tomorrow they brought turned the world to ash. With the world steadily dying around them, Elfnein hits on a plan to undo this bad ending - but it all hinges on the next generation of Symphogear-users.
Relationships: Kohinata Miku/Tachibana Hibiki
Kudos: 9





	Resonance

_"This is the world of tomorrow that you brought forth!"_

-

She walks through the ash piled high like snow. No clicks from her geiger counter, so the radiation storms have passed. The ash soaks it up somehow - you'd get sick if you ate it or breathed it, but you can walk through it just fine. The scientists were still debating how it worked, bemoaning that it only appeared now. The ones that didn't have Seal Sickness, anyway. Her own family weren't doing so well in that regard either - Hibiki had largely shrugged it off, her status as Godslayer seemingly making her immune; Miku had dodged the delerium and crippling fever, but wasn't well enough to walk. That their adopted daughter hadn't developed the Seal was both blessing and curse - blessing, that she didn't develop Sickness; curse, that the Locusts came for her.  
Of course, they weren't really locusts. Well, some of them were. They were what was left of the animals and plants on Earth, their forms twisted and ravaged, each one enough for a lifetime of nightmares. You either died of Seal Sickness, or you were attacked by the Locusts. They came out of the ash storms like ghosts, chittering and clicking, and took their pounds of flesh in the limbs and guts of their prey. In fact, she can hear them now, coming for her. This is all she can do, right now - she can go out of the shelters, lure the Locusts, and cull them, making it that much safer for the less-lucky to salvage anything they can from what's left of their shattered civilizations.

She puts her hand over her chest, feeling the red crystal under her suit, and sings softly, through her mask.  


> **"Valwisya kiyedven Gungnir zizzl...!"**

She's wrapped in the white-and-gold of her Symphogear, doing away with her mask and suit. Like Hibiki, her Gungnir wields no spear, but she also lacks the legendary white scarves, and the whole Gear has developed a hint of rust and cracks - even when Elfnein restored them, after their phonic signatures shifted, they'd never fully recovered from the damage. She was lucky that Hibiki's worked on its own at all; others had to be abandoned or melded, and that was assuming they could even find users.  
The blast of energy washes away the ash around her, revealing the frozen grass underneath - and the Locusts. Only three of them today, but more will come. None of them are an easy category to identify, since their forms are so mixed up, practically random amalgamations of black flesh studded through with red veins and bright eyes, not in the right places, half-formed wings at the wrong angles, claws bright with venom...

It had begun on the day Shem-Ha accelerated the Earth, trying to block out the solar radiation that prevented the creation of the bio-terminal network - otherwise known as 'humanity'. Her family had defeated Shem-Ha and destroyed the Yggdrasil, the network built into the planet. They'd thought everything would go happily ever after from then on, with the Curse of Balal lifted and the world united in its efforts against the God Shem-Ha.  
They didn't notice until it was too late. The acceleration of the planet, both its orbit and its spin, slowly ruined it. First it came in shorter days and shorter nights, shorter years. The rapid seasonal shifts ruined the already-precarious ecosystem. Then the after-effects of the destruction of Yggdrasil began coming down - the Seal Sickness, the atmosphere peeling and creating radiation storms, the fauna rapidly mutating to survive, becoming the Locusts that hunted the healthy humans. They only lived in shelters, now, only emerging to salvage what leftovers of civilization they could.  
Even SONG could only do so much. When the seven Symphogear-users synchronized their phonic gain to take control of Yggdrasil and cause it to self-destruct using the perfect scale, the resonance flowed backwards as well, changing the frequency the relics responded to; in short, the Symphogear-users were that no longer.  
That's how they'd found her: an orphan working with building crews, scampering the scaffolding and sometimes singing as she worked. SONG had pulled her in for an aptitude test, and her song had triggered the repaired Gungnir. Working so closely with Hibiki to master it (and Hibiki and Miku were never likely to be apart, even after they developed Seal Sickness), the pair had first informally, and then formally adopted her. She'd chosen her own name, though.

Yari, the spear.

Gungnir provides it on its own, the high energy synth-pop and bagpipes that make up its signature sound. Yari doesn't need to focus on it; the words of the song come out on their own, rolling up from her heart.  
" _This world where hope was found, this world where hope was lost / This world that's only as wide as my fists can reach!_ " She lashes out as the first Locust approaches her, driving a fist-shaped crater into its black flesh - it's more like a horrid mix of chitin and tar, but it reels in pain, wildly flailing with those wicked claws. Yari doesn't hesitate to follow up; just as Hibiki taught her, she steps through the barrage and follows up with another blow, power coming from her hips, following the shortest, straightest, most direct route, her fists landing like steam hammers. " _But that's alright for me, because in this tiny world / Everything I want is in my hands and I won't let go!_ "  
Yari shifts sideways, pivoting off her front foot to step aside a barrage of energy blasts - their eyes can do that, and it never fails to give her the creeps - and coming around to bring her heel in a circle around her body, smashing clean through one of its wing-analogues. She's keeping it between her and the other two Locusts, using it as a shield from their own; whatever they were before, they work together now, and they won't attack each other. " _The love I never knew, the pain of having family / These fists accept it all, we're bound by these scars...!_ " The Locust uses its heavy claw to slice at her from underneath, and Yari spins over it, delivering a deathblow to its center body - it slams into the ground so hard that the frozen grass around it shatters like glass, bloated torso nearly punched through by the impact. These are the fists that felled the gods, after all.

She turns to the remaining two, as they try to circle around her for a pincer attack. " _Even if I lose, even if I'm hurt / Everything I want is right here in my fists!_ " Yari spins low, ducking a claw slash and responding by bouncing onto both hands and springing off, driving a kick into its... jaw? This one has long mandibles, one of which is rendered cracked and useless by the blow. " _When you're lost, REACH OUT! When you're hurt, REACH OUT! / Your fist is the spear that pierces gods and devils! / To your friends, REACH OUT! To your foes, REACH OUT! / Your fist is the spear that pierces this tiny world!_ " Yari whirls on her hands, bringing her greaved heel around into a skull-cracking blow that slams the Locust to the frosty ground and brings her back onto her feet, half-turning to try and find the other one. " _The hope in these fists is the sunshine of this wo_ -!"  
She's cut off by the last Locust hitting her head on, buffeting her with its wings and smashing her to the ground. It pins her there while the second Locust starts to recover, but the one that's on her raises its wings high, red flames crackling between them as it prepares to vaporize her...  
And then another voice rings out through the dark air.

> " **Zeivarize Zababa tron...!"**

A pink-and-black buzzsaw slashes through the Locust pinning Yari down, and she rolls out from under it, quickly springing to her feet. "Why are the Blades of Zababa -"  
"We can talk later." The girl bounces in front of her, more shadow than person, her figure lit only by the glowing green-and-pink highlights of her Gear. Famously mutable, the Blades of Zababa compliment one another perfectly; the scythe in her hands transforms into a wicked hooked chain, and she lashes out, catching the launched buzzsaw and dragging it back around for a second pass. Just as the Locust looks like it's about to dodge, though, the buzzsaw blade suddenly splits in half, transforming into two smaller blades that rip through it, spilling bits and pieces of it, like chalky ink, over the earth.

> **UNIFIED STYLE TWIN MOON BLADE**

"It's not over. Keep singing."  
Yari nods as they square up to the last one. Her concern was that it would scream and draw more, but instead it converts that energy right into itself, its crackling flames drawn _into_ its body, rapidly accelerating its own mutations - its body swells and bloats, eyes lining the gaps as its skin rips open, no longer able to contain the bulging tissue. Yari takes a breath and focuses herself as her friend keeps it busy, dancing around it and harassing it from all angles, a green-and-pink blur only just visible in the murky ash and frozen grass.  
" _The hope in these fists is the sunshine of this world! This hope, this life, this love!_ " Hibiki had never grasped using her Armed Gear for real - instead, she converted the energy directly into her Gear and slammed it into them. Yari is self-taught as a result, and her style is different still: she holds the golden-orange flame in her fists, willing it larger and larger. " _Ring out, sing out, let your howl be heard throughout the world!_ " And then she raises her hand and squeezes her fist shut, turning the swelling flame into a golden bolt in her hand, like the thunderbolt of Zeus. " _I'll never turn my back, on this cold and dying world / My fists will reach out, bring light and love to the horizon!_ "

> **  
> **
> 
> **GODSLAYING∞SPEAR**

**  
**

She hurls it and it leaps from her hands like a bolt of red lightning, blasting clean through the mutant Locust - the hole is small at first, but then the shockwave catches up and explodes it ouwards. Smoking, it collapses to the ground, starting to turn to ash. For just a moment, the shockwave from the attack splits the murky clouds... but there's nothing to see, now, with the sky tinted red like blood.

The girls don't cancel their transformations - it's nicer to talk face to face, after all. "... let's go back. Why are you here, Hakuba?" With the girl's movement stopped, she's still kind of hard to get a bead on; she's small, but in a 'compact' sense rather than just being tiny. Her Relic is the Blades of Zababa, combined to stabilize their phonic waveform, and her Gear's form combines aspects of the users she inherited from - Shirabe's buzzsaw-greaves that let her skate across the ground and the rabbit-ear holders (which are instead on her shoulders, like wings), but Kirika's skirt, bodice, and peaked cap, worn so low that only one red eye is reliably visible. Hers comes with a full, black bodysuit though, along with a long, black scarf that works as a muffler, covering most of her face. She's only lit by the Gear itself, its neon lights occasionally glittering and turning her from a shadow into a person. "I've come to pick you up. Elfnein-sensei needs us."  
"Elfnein? Why?" By contrast, Yari is hard and kind of flinty, always holding herself like she's ready for a fight, with long limbs that make her all angles when she stands upright. Fit and tanned, she has blue eyes that are so pale they're almost grey, and dark hair that she wears with a single golden streak in it, by way of homage to Hibiki. "Did something happen?"  
"... who knows. I didn't ask."

Of course. That's how Hakuba lives her life; by only paying attention to what's right in front of her and blocking everything else out of her mind. Her laser-focused determination has saved Yari's life more than once, but at the same time, she can't help but wish Hakuba would be a bit more flexible. Even Yari can't talk, though; her world is only what she can hold in her hands: her friends and family.  
"I need to let Hibiki and Miku know."  
"They're already on their way." They have Seal Sickness, so it's safe for them to move around, provided they take precautions against the pollution. "Come. The Chateau isn't far."

* * *

What's left of the Chateau is more like it. Once a gigantic tuning fork dedicated to dissecting the world, Elfnein has managed to use it to constantly emit a frequency that is inaudible to most people (it gives Yari a headache if she hangs around too long, though) but keeps the Locusts away. More important is the alchemical laboratory that her alter ego, Carol, once used. As an homonculus, Elfnein hasn't grown; while the others are now adults, and Genjuurou is becoming a silver fox, Elfnein is as petite as ever. She's still wearing her oversized labcoat, the closest thing she has to a prized possession.  
Hibiki and Miku look worse than when Yari saw them that morning, exhaustion from the trip coupling with the Seal Sickness to make both of them unhappy. Hibiki is wide awake, looking like she's using sheer force of will to stave off the Seal Sickness, even as the words scrawled onto her skin angrily pulse and writhe, trying to find purchase. They're calmer on Miku's body (although she's well and truly rugged up), but Hibiki's stamina is legendary and Miku's... isn't, so she's worn out and dozing on Hibiki's shoulder.  
"How is she?" Yari checks in with Hibiki, who gives her one of her radiant smiles - although it's certainly not without its tiredness. "She'll be okay. Just worn out from dragging herself through the ash." She says that, but she's still fiddling with the ring on her finger nervously, like she always does when Miku's having a bad day. When she catches Yari looking, Hibiki forces a laugh and changes tack. "S-so, Elfnein-chan, what's wrong?"

Elfnein has been fiddling around in the work floor of the lab, while the others are seated at the observation deck, fiddling with something that Hibiki thinks looks familiar. Genjuurou, however, who has retained his monstrous physique even as his hair greys, recognises it immediately, and calls down in his loud voice. "You've remade Sakurai Ryoko's lab?"  
"Something like that. I had an idea about how we can fix things. Or something close to it." Elfnein straightens up from the central podium, where she has what seems to be a smaller tuning fork suspended in a gravity field, glowing gently. "This was made from the Relic Prajnastra, which was sent to me by Kirika-san and Shirabe-san. According to the Hindu Epics, Prajnastra was used to restore senses and thoughts." Yari exchanges a glance with Hakuba at the mention of her predecessors, but her face is completely devoid of expression as usual, and Elfnein continues. "Fiine used a specific waveform assosciated with the Symphogear she created, the Aufwachen Waveform, to awaken her consciousness within her descendants. Thanks to Carol's research, we know that the seven notes in the scale of song function as an access code to universal language. Therefore, I had an idea."  
"What if, instead of projecting phonic gain through space, I tried to project it through time? Actually, I've already succeeded at transmitting a phonic waveform into the past."  
Everyone is silent for a moment, but it's Genjuurou who asks the question. "Then... isn't that..."  
"That's right," Elfnein nods. "It's a time machine."

Elfnein tucks her hands behind her back. "It is apparent that this situation is beyond salvaging. Once the Seal Sickness began spreading, and we lost any ability to try and return the planet to its natural orbit and rotation, the focus of my research changed from 'fixing this situation' to 'preventing the situation'. I can only send phonic waveforms back in time - and then only to this same Relic - but I believe this may provide the solution. However..." Her expression sours. Elfnein is no longer shy to say what she thinks, but that doesn't mean she has to like it. "... there are problems."  
"First," she holds up a hand, one finger raised, "at the moment, I can only send information back to this Relic. Thus far, I've arranged it so that information will arrive as soon as my past self completes and activates the Prajnastra relic here. It should be possible to send information to the Relic in its dormant state, but that is only an educated guess. I obviously can't test it in any reliable way. And, obviously, by the time my past self activates Prajnastra, this situation is too far gone to salvage. After all, I only activated it last night. I believe that 'I' have repeated this process of receiving my research and sending it back in time several dozen or even several hundred times.  
"Second, no matter if I could change the course of history, this world is still doomed. If the timeline is severed, the world may simply cease to have ever existed anymore; if a new world is created, this world will continue its course towards death.  
"Third, the only people capable of generating a sufficiently powerful, stable phonic waveform are Symphogear-users, and we only have two here. Tsubasa-san and Maria-san have a suitable candidate in London they've been training, but travel is dangerous, so they can't be counted on. In other words, at most we could send back the waveforms of Yari-san and Hakuba-san. Which is to say, I will use your phonic waveforms to encode your consciousness, and send you back to the dormant Relic. When the relic is exposed to any phonic gain - which it will be - it will resonate with your phonic waveforms, and awaken your consciousnesses in the past.  
"Fourth... to do so, it will project your consciousnesses into suitable containers. That is to say, the 'you' in the past. In effect, your present selves will overwrite your past selves, killing them."

Yari and Hakuba both grew up in weirdness - they're not that much younger than Hibiki and Miku, maybe ten years or so, so world-shattering events and strangeness are normal to them. They exchange another glance as they take on Elfnein's suggestion. Yari's question is about a more complex subject than time travel. "... so we abandon this world? We just... give up?"  
"Not to mention, the part where we basically kill and replace our past selves..." It's unusual for Hakuba to complain about that sort of thing, but she's definitely weirded out by this. "... for once, I don't know how I feel about that."  
Actually, the fact that she's admitting she has feelings at all is already a surprise to Yari, who follows up. "I know you're saying this world's already too far gone, but it's our world. And there are more people than us who live in it, can we really just... arbitrarily decide to give up on it?"

She stiffens as a hand lands on the back of her neck, squeezing her and drawing her closer - Miku, who is barely awake. She has to pull Yari to her to talk to her properly, since her voice is so quiet, but even though her voice is weak, her grip is still strong. "We aren't giving up." Hibiki nods, while Genjuurou is unusually pensieve, as if considering. Miku continues softly, her bright eyes meeting Yari's. "We'll keep doing everything we can... like we always do. No matter what happens here."  
"Right. Don't worry, it'll be alright." Hibiki's catch phrase comes out with a sunny smile, and she ruffles Yari's hair as Miku releases her, sinking back into a doze. "We'll keep fighting here. This isn't surrender. It's a two-pronged attack!"  
"Something you've never been accused of, Hibiki-san," Elfnein teases her, making Hibiki pout. The smile fades off her face quickly though, and she looks to Genjuurou. "Commander." He hasn't been that in a while, but old habits die hard. "I believe that this is our best chance. Regardless of what pans out, however, we will lose the present Hakuba-san and Yari-san, and with them our Symphogear-using potential. This is a huge risk, with a huge reward."

Genjuurou, arms folded, is silent for a long time. Even now, he's a bear of a man. After almost a full minute, he looks to Yari and Hakuba. "This idea puts everything on you two, and I've never been your commander. You can make your own decisions. Whichever you decide, we'll abide by it." He looks at Elfnein, who bites her lip and nods, obviously wanting to argue the point, but unable to dispute the sentiment.  
Hakuba is silent, playing absently with her bangs - her body language for when she wants nothing to do with a situation. This is how she copes; she becomes a tool that others can use. In other words, it's entirely on Yari as to what they do. She's about to open her mouth when Miku has another coughing fit; Hibiki wraps an arm around her to keep her upright as the shuddering coughs wrack her body, making her squirm and buck in her seat. When it subsides, the tissue Hibiki was holding to her mouth comes away stained with the odd mix of blood and ink that Sealing Sickness produces.

"We're in."

Yari's mind is made up. She can't let people keep suffering like this. Even if she still feels like it's running away, a chance for a better world is worthwhile, right? She looks at Hakuba, waiting to see if she says otherwise, but the stoic girl barely nods her head, her tacit agreement. Elfnein gestures them to the hovering relic. "Then... please come here, and sing your swan songs."  
Yari takes a moment first, embracing Hibiki and Miku and being embraced in turn, squeezing her adoptive parents tight. "I love you." It's the first time she's said it openly to them, catching them both by surprise, but they squeeze her tighter in turn, both of them smiling.  
"Go get 'em. No matter what, you're family."  
"... I know." She doesn't say goodbye. "... see you later."

Hakuba is waiting for her by the relic, and she offers her hand as Yari approaches. Yari takes it, squeezing gently, and she can feel Hakuba trembling, just a little. The squeeze calms her a little, though. She doesn't quite smile, but her lips quirk in a way that suggests it. The two take a breath and sing, voices mingled together.

> ****
> 
> ****"Gatrandis babel ziggurat edenal  
>  Emustolronzen fine el baral zizzl  
>  Gatrandis babel ziggurat edenal  
>  Emustolronzen fine el zizzl..." 

**Author's Note:**

> Wrote this to get the brainworms out because the lack of attention paid to what would be an apocalyptic event at the end of XV always tilted me. Might expand on it more, but for now it's a one-shot.


End file.
